The invention relates to a camera monitoring system for preventing a transformer from being stolen, and the system is disposed on an outdoor transformer. The system comprises a multimedia processing camera, an infrared sensor, a data storage unit, and a remote monitoring terminal. The multimedia processing camera is connected with the infrared sensor, the data storage unit and the remote monitoring terminal, and comprises a video input board, a main processor board, and a power interface board, wherein the video input board, the main processor board and the power interface board are connected sequentially. The main processor board is connected with the infrared sensor, the data storage unit and the remote monitoring terminal. The video input board collects on-site video data of the transformer in real time, and the on-site video data is stored in the data storage unit after being processed by the main processor board. Meanwhile, the main processor board receives an induction signal of the infrared sensor in real time. When an alarm signal is generated, the main processor board enables the video data collected by the video input board to be transmitted to the remote monitoring terminal. Compared with the prior art, the system is high in image quality, and effectively reduces the theft times.